Just about everybody with the power to protect her from Jared Remy after he first attacked her in their Waltham home let her down. They overestimated him, deciding he would not attack her again – let alone kill her in the gruesome way he did.

The thing is, there shouldn’t have been much to guess about here. We know so much about domestic violence now, its patterns, numbing frequency, and lethal potential — 10 deaths already this year. We can tell with some accuracy which abusers are most likely to attempt murder. Jacquelyn Campbell, a professor of nursing at Johns Hopkins University, has led the way here, creating a checklist of risk factors: a history of abuse, substance issues, choking a partner, attempts to control her social life — all increase the likelihood that an abuser will turn to murder.

Remy exhibited enough of the factors — steroid abuse, grabbing Martel by the neck, a history of domestic abuse, attempts to control her — to put him in the “increased risk” category. Campbell would have elevated the risk level to “severe” if Martel had told Remy of her plans to leave him.

The beauty of this systematic approach is that it takes the onus off the victim to decide how much danger she’s in. Campbell’s research shows that victims tend to badly underestimate the risks.

In her attempts to explain the decision not to try to hold Remy last week, Middlesex DA Marian Ryan — who leads an office with a stellar reputation for handling domestic violence cases — cited Martel’s decision not to renew a restraining order against Remy as a contributing factor. That’s not just inept; it’s ignorant. Domestic violence advocates say Martel’s choice was an obvious and long-recognized red flag — an indicator that the victim is feeling afraid, or pressured.

There is a better way. In some Massachusetts cities, law enforcement and domestic violence advocates work together in teams to prevent domestic homicide: An officer responding to a call administers a danger assessment test on the spot, and connects a victim with advocates from the local community who can help steer her through the system in her terrified state. It’s an approach pioneered by the Jeanne Geiger Crisis Center, in Newburyport, which has helped launch such teams in two dozen communities, where domestic homicides subsequently fell to zero.

If the program had been in place in Waltham, police would have conducted a risk assessment interview to build as full a report as possible on Remy’s first attack; they would have called a local domestic violence advocate immediately to help Martel get to safety and make clearer decisions about whether to pursue a restraining order; they would have monitored her closely through the following weeks and months.

But there is no high-risk team in Waltham. This may be the result of funding or red tape. Or perhaps, some surmise, it’s because the chief who led the city’s Police Department until a month ago was himself convicted of domestic abuse. Whatever the cause, “we could not get any traction” in the city, says Laura Van Zandt, executive director of the city’s REACH Beyond Domestic Violence organization. “We have good relationships with the officers, but it has been very hard to deal with the department.” A victim advocate from the DA’s office did speak with Martel after the attack, but no counselors from REACH had contact with her.

Could Martel have been saved if more had been done? We’ll never know. But her life was worth every missed chance, and more.